Instructions
The Daylight Estimator is a Sun Tunnel calculator tool that will  give you  the amount of light you'll get in a room based on your input.

1. Select the product (ies file) that represents the desired daylighting device (Luminaire)

Daylighting products are listed by product type, size, length of tunnel, and sun angle.

For example:
TCR-22in-4ft-40sky.ies is a curb mount 22” TCR Sun Tunnel with 4ft of tunnel and represents product performance under an average 40 degree sun angle. This sun angle is ideal for estimating the number of tunnels needed. The 40 degree sun angle can be experience between the following times throughout the year:

In March between 9:00 am–10:00 am
In April between 8:20 am–9:00 am
In June between 8:15 am–8:20 am

A corresponding high 80 degree sun angle is available to understand peak light output experience at high noon in June.

To help identify the correct products, click on the Show Luminare image to see a picture of the products or if more detail is needed to back to our product selection section at: https://www.veluxusa.com/products.

Daylight estimator step 1

2. Define geometry of the space

Select the length, width, and ceiling height of the space. The work plane height should be 2.5' for most applications and the suspension length refers to the length that the diffuser penetrates the ceiling height, for most applications this should be set to 0. In open ceiling applications, the ceiling height is equal to the height of the roof and the suspension length will be set to something other than 0, if unknown, 2.5' is a good default value to use.
Daylight estimator step 2

3. Define room reflectance

If the reflectance values of the space is known, insert them here, otherwise, use the following default values:

  • Ceiling: 80%
  • Walls: 50%
  • Floor: 20%
Daylight estimator step 3

4. Specify number of Daylighting devices or desired illuminance (foot candles)

Either specify the illuminance which quickly is translated to a foot candle value or enter the number of daylighting products. If you enter an illuminance value, the program will automatically display the equivalent foot candle equivalent and tell you how many daylighting devices will be needed to achieve these results. If you specify a number of daylighting devices, the program will tell you how many foot candles this number of daylight devices will produce on average in the defined space.
Daylight estimator step 4

Optional steps

5. Advanced Layout
  • Further define the spacing criteria for the daylighting devices
6. Advanced Luminaire section
  • Change the space of the foot print from round to square and vice versa
7. Units
  • Select the desired units of measure
8. Output
  • Add a project title and description
  • Print a summary of the results